The proposed research will investigate the nature and extent of DNA polymorphism in various tick species as identified through agarose gel electrophoresis of random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Ticks are major vectors of many pathogen organisms which affect humans and their domestic animals. The proposed research will provide the initial investigations of DNA polymorphism, primarily in the moderately repetitive segments, of the tick genome. These areas of the genomes have not been investigated in ticks and offer a potential weather of information on the basic genetics and how characters for the construction and testing of tick phylogeny and systematics. Previously investigated areas of the genome have employed multi locus enzyme electrophoresis and RFLP or DNA sequence data in the nuclear and mitochondrial ribosomal DNA, which are under a different level of selection than the areas most frequently sampled by RAPD-PCR. The research also proposed to construct molecular cytogenetic probes to be used in fluorescent in situ hybridization (FISH) to localized and characterize specific DNA segments within the tick genome. RAPD-PCR data will be collected on all the available tick species using wild caught laboratory reared, or cell lines as the DNA source. Species to be investigated include most species of North American ticks that are known to be major disease vectors. Investigations of each individual will include DNA extraction, RAPD-PCR, agarose gel electrophoresis, and analysis of each genetic relatedness using phenetic and phylogenetic approaches. Molecular cytogenetic probes constructed will be used to investigate the movement and/or lose of material in the genome of North American ticks. The data will be applied to the poorly understood area of tick genetics and extended into tick biology, physiology, systematics, and biological control systems.